Rotary boring drill



F. l.. 0. WAUSWORTH.

ROTARY BORING DRILL.

APPLlc/mow FILED MAY 10. 1920.

Patented Mar. 7, 1922.

UNITED STA TES PATENT oFFicE.

FRANK L. 0. WADSWORTH, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 HUGHES TOOL COMPANY, OF HOUSTON, TEXAS, A. CORPORATION 0F TEXAS.

Specification of Letters Patent.

Original application led May 26, '1919, Serial No. 300,004. Divided and this application filed May 10, 1920. Serial No. 380,033.

To all wim/m, t may concern:

Be it known that I, FRANK L. O. WADS- WORTH, a. citizen of the United States, residing at Pittsburgh, Pennsylvania, yhave invented a certain new ment in Rotary Boring Drills, of which the following is a full, clear, and exact description, such as will enable othersA skilled in the art to which it appertains to make and use the same. v

lThis invention relates to a particular species of .the construction generically disclosed in my copending application N o. 300,- 004, filed May 26, 1919, now Patent Number 1,374,867 issued April 12th, 1921, from which this application has been divided. It relates to improvements in rotary boring drills of the roller bit type and more partlcularly to drills which are provided with disc shaped cutters, and whic-h are designed for drilling oil or water wells of moderate depth. Drills of this general character generally comprise a head which is threaded at the upper end for attachment t0 a rotary drill stemrand which is provided at its forward end with a pair of disc shaped cutters that are mounted to rotate, on axes transverse to the longitu dinal axis of the head'. The matter which is cut away and 'disintegrated by the drill is Washed away from the cutters and carried to the surface by a stream of flushing water introduced under pressure through the hollow drill stem Aand through channels in the head of the bit. t

4@ne object of my invention is to mount the cutters of the drilling tool, in such a manner as to attain the most effective cutting and Vdisintegrating action when the drill is operated in strata of varying hardness.

Anotherobj ect of these improvements is to provide cutting members, whose form and arrangement are such that a part of the cutting operation will be performed by the rear or following edges of the said members.-

Still another object of this invention is to pro-vide the cutting members with teeth of such form as to facilitate the rotation of the cutting elements upon their own axes as the drill head is revolved.

A further object of my present invention is to arrange the cutting members in such relation to the aXis of the drill head that the side thrust of the cutting strains is directed toward the said axis, instead of away from and useful Improveit, as in the usual struction, v Additional objects and purposes of these improvements are the provision of a novel form of cutting edge on the outer faces of the. rotatable disc members and the pr vision of a novel bearing support for the said members. Other objects and advantages of my improvements will more clearly appear in the following description of several illustrative embodiments of my invention.

In the drawings, wherein like characters refer to like parts throughout the different views, Fig. 1 showing the preferred embodiment of my invention; Fig. 2 is a transverse section on the double plane 2-2 of Fig. 1; Fig. 3 is a side elevation of the head, as viewed at right angles to the plane of Fig. 1.

In the preferred embodiment of my invention, as depicted in Figs. drawings, the cutting members 13"-13y are mounted directly opposite each other upon the base of the head, 11. The head is made up of a cylindriealshaped body having an upper Ithreaded shank 12, for attaching it to the drill stem by which it is operated. The revolvable cutter lmembers are housed in a central slot in the base of the head. 'The sides ofthe housing slot are flared outwardly; and, each cutter is mounted o-n a separate inclined pin or shaft 14V, which is provided with fitting within a corresponding recessl in `the outer face of the head.

In this organization the inner ends of cutter supports, 1115', are reversely beveled,-as shown in Fig. 1 and the cutters, which are mounted upon these supports, are spaced apart by a central wedge shaped washer 38. Theparts are held in their assembled position, in the head, by means of a bolt 36 that is threaded into the right hand shaft 143; and after the parts are drawn tightly into position, by screwing home this bolt, the threaded end thereof is headed over to prevent its accidental loosening. When it is desired to remove the parts, the headed over portion is cut away with a tile or cold-chisel; and when the parts are re-assembled again a. new bolt is, if necessary', used for again' securing them in place in the manner just described. In thls construction astream of form of disc drill conan outer thickened head 27V..

Patented, Mar. 7, 1922.

l, 2 and 3 o-f the flushing water is supplie-d through a single central tube 185', which leads from the top of the drill head to the slot in which the ing this central tube; and passage ways 201" lead from the lower. end of this pocket to corresponding grooves or apertures, formed inthe shafts 14? and communicatmg, at

' proper points, with the bearing surfaces of the bushings SQY. This lubricant pocket 41 is closed at the top with a suitable screw cap 40 which is preferably threaded on the tube 18", although it may, if desired, be threaded directly into the upper end of the lubricant chamber in the drill head.

The disc members of this embodiment of my invention may be made solid; but, as indicated in plan view in Fig. 2, they are preferably each composed of two parts, which are capable of revolving independently on the shaft 14H, or on the bushing 32% In this case. the rolling or revolving movement of the inner parts, which carry the advancing edges Qy, may be slightly different from the rolling movement of the outer parts, which carry the following edges QGY; and as a result of these differen-4 tial movements,-which are produced by the engagement of the peripheral faces of the parts with the bottom of the bore hole at different distances fromY the axis of rota-V tion-a more effective cutting action of the independently moving edges, and a more effective crushing action of the peripheral faces between those edges, may, under certain conditions, be secured. The outer faces of the discs are recessed, to provide sharp cutting edges 26Y on the rearward following sides of the revolving members.

The operation of my improved boring drill will be readil understood. The head of the bit is rotate in a clockwise direction;-

the rotating head. The shearing and cut# ting action of the oppositely inclined teeth, on the peripheral edges of the disc members, induces a semi-posit1ve revolution of those members in the same direction in which they tend to rollon the bottom of the hole, and

' thus causes them todpresent a continually changing cutting an crushing surface to the material being drilled. The provision of the recesses on the outer sides of the disc members, and the resultant cutting action of the rearward following sides thereof, 3ro# duces an inwardly vdirected thrust on the revolving members, that serves to hold them in close operative engagement with the central portions ofthe head supports ;l and this relieves to some extent the transverse strains on the shaft bearings, and materially stift'ens the relatively thin disc elements against the pressures of the cut.

The division of each cutter member into two parts allows a differential movement of the inner and outer'disc elements; and the inclined teeth on the vperipheries of the independently rotatable discsare permitted to act .more directly in assisting the rotation thereof. In these embodiments the inner faces of the inner discs shear away the material from the sides of the hole on the fory ward advancing sides of the rotatable members; and the outer recessed faces of the outer discs shear away the material which is in engagement with the rearward fol lowing sides of those members; and the vloose material thus removed is very rapidly disintegrated and pulverized by the differential rolling movement of the toothed peripheral surfaces over the bottom and side walls of the bore cavity.

The operative advantages of my present improvements will now be apparent: The

provision of sharp cutting edges on the outer faces of the cutter members and the shaping of the disc peripheries to conform to the curvatureof the hole, makes it unnecessar to provide any clearance for the discs by effi# setting them one'from the other, as is now customary; and as a result of this the rapidity of the cutting and crushing operations is increased; the number of points of Contact between the revolving members and the walls of the boreV hole are substantially doubled; and the steadiness of action of the rotating drill head is thereby materially im.- proved. The provision of oppositely inclined, or herring bone, teeth on the peripheries of the cutting discs, andthe positioning of these teeth in such relation thereto that the rotation of the drill head produces a semi positive rollin or revolving movement of the said discs, will eliminate, or overcome to a marked degree, the tendenc Aof this type of drill to become balled up? in soft formation; and the joint provision of double acting or two edged cutting members,having cutting edges on both the advancing and following sides of the said members-and of means for ensuring their rindependent revolution, willl secure` a more effective and rapid comminution ofthe material after it is cut away from the sides of the bore hole; and will also secure a more complete and continuous mixture and sus- `pension of the finely divided material in the currents of flushing water which are flowing downwardly over the forwardly advancing faces, andy upwardly with-therearward following edges of the-revolving'cutters.

Having thus described my invention, what I claim as new and desire tovprotect by,Let ters Patent, is: f

l. In a rotary boring` drill, the combination with a drill head of two disc-shapedl cutters set exactly opposite each other, and adapted to drill the full gauge of the hole, said cutters being rotatably mounted on axes transverse to the longitudinal axis of the drill headthe outer faceof each cutter being dishedto provide a cutting edge on the rearward following side thereof.

2. In a rotary boring drill, the combination with a drill head of two opposite discshaped cutters rotatably mounted on axes transverse to the longitudinal axis of the drill head and provided with cutting edges on both the forward side and the rearward following sides, the outer periphery of the said cutters being toothed on both edges in such manner as to assist in the rotation thereof. Y

3. A rotary boring drill comprising a head with two opposite cutting discs mounted on axes transverse to the longitudinal axis of the head, and having sharp cutting edges'on both the outer and inner faces to shear away material in contact with both the advancing and following sides thereof.

d. A rotary boring drill comprising a head with two opposite cutting discs mounted on axes transverse to the longitudinal axis of the head and provided withsharp cutting edges on both faces thereof, the peripheral surfaces of the said cutters being shaped to conform to the curvature of the hole.

5. A rotary boring drill comprising a head and two opposite cutting discs mounted on the forward end thereof and so disposed thereon that their rearward following edges engage with the wall of the hole to, be drilled, the peripheryof the cutters being provided with teeth extending at an angle downwardly and backwardly from the rearward following edge and upwardly and backwardly from 4the forward advancing edge.

6. A rotary boring drill comprising a head and two opposite cutting discs mounted on the forward end thereof on axes transverse to the longitudinal aXis of the head, the outer face of each cutter being recessed to .provide a sharp cutting edge thereon, and

both peripheral edges of the said cutters being shaped to conform to a common surface of revolution.

7. In a rotary boring drill, the combination of a head, a support at the lower end thereof, two bearing shafts secured on said support, and opposite cutting discs mounted on said bearing shafts, each of the said discs having a broad milling surface and a sharp` cutting edge on each side of said milling surface. l.

8. In a rotary boring drill, the combmation of a head, and two oppositely disposed cutting discs rotatably mounted on the lower end thereof, adapted to cut the full diameter of the hole, each of the said discs having a; broad peripheral milling surface and asharp cutting edge on each side thereof.

9. In a rotary boring drill, the combination of two opposite cutting discs rotatably mountedzon shafts in the base thereof, the periphery of, said discs being curved to conform to the shape of a hole and provided with sharp cutting edges on both faces to engage the walls of the bore hole on both sides thereof.

10. In a rotary boring drill, the combination of a head and opposite cutting discs mretatably mounted thereon, the periphery of each of said discs being rounded to conform to the shape of the hole, and the smaller outer portion thereof being extended lateralily to form a comparatively sharp cutting e ge.

11. A rotary boring drill comprising a head, with two oppositely disposed cutting discs mounted on axes inclined to the longi tudinal axis of the'head, each of said discs having sharp cutting edges on both the inner and outer sides thereof and toothed peripheral faces that are shaped to conform to the curvature of the hole.

12. In a rotary boring drill, the combination of a head and two oppositely disposed disc-shaped cutters mounted on axes inclined to the longitudinal axis of the head and 'adapted to cut the full bottom of the hole, the peripheral faces of each of the said cutters being toothed and shaped to conform to the curvature of the side and. bottom of the bore hole.

13. A rotary boring drill comprising a head and two oppositely disposed cutting discs mounted on axes transverse to the longitudinal axis of the head and inclined thereto, each of the said discs having sharp cutting edges on both sides thereof and peripheral faces which are toothed and shaped to conform to the curvature of the hole, the teeth on said peripheral faces be ing inclined downwardly and backwardly from the rearward following edge. y

14. A rotary lboring drill comprising a head and two oppositely disposed cutting members, mounted at an angle to each other on the said head, thei inner face of each member being substantially smooth and the outer face thereof being recessed to provide sharp cutting -edges on both faces of the said members. Y

15. In a rotary boring drill, the combination of ahead and two oppositely disposed sets of cutting discs mounted rotatably in slots in the forward end of said head, each of said setsof discs comprising two smooth contiguous sections capable of independent rotation and each section being provided with peripheral cutting teeth so inclined as to effect a screw action to assist in the rotation thereof.

16. In a rotary boring drill, the combination of a head, cutting discs journalled rotatablp7 on bearing pins at the forward end of` said head, lubricating meansv for said bearing pins which comprise a central tubular recess in the upper end of the said head and ducts leading from said recess to the said pins, a water pipe passing through the said recess and threaded into the lower end thereof, and a cap engaging with said water pipe and closing the top ofthe said recess.'

17.111 a rotary boring drill, a head and two disc-shaped cutters rotatably mounted on axes-in the base thereof; the said head having alongitudinal cavity closed at the bottom, oil ducts leading from said cavity to the cutter axes, a central tube in said cavity threaded into the closed end thereof, and a cover plate threaded on said tube, and adapted to close the top of said cavity.

18. In. a. rotary boring dr1ll, the combination of a head and two sets of cutting discs, each of vthe said sets being composed of two contiguous rotatable Sections, one of the said sectionsv being adapted to cut with the rearward following edge, and the other with the forward advancing edge, the inward thrust on one' cutter being opposed to the outward thrust on the other.

In testimony whereof, I hereunto affix my signature this the 8th day of May, A. D.,

FRANK L. o. WADsWoRTH. 

